Process of reducing zinc from its oxids, &amp; c.



WILHELM SCHULTE, OF OVERPELT-LEZ-NEERPELT, NEAR LIMBURG, BELGIUM.

PROCESS OF REDUCING ZINC FROM ITS OXIDS, 8L0- SPECIFICATION forming part of Letters Patent No. 718,222, dated January 13,1903.

I Application filed April 22, 1902. Serial No. 104,195. (No specimens.)

To all whom it may concern:

Be it known that I, WILHELM ScHULTE, a subject of the King of Prussia, residing in Overpelt-lez-Neerpelt, near Limburg, in the Kingdom of Belgium, have invented new and useful Improvements in the Process for the Reduction of Zinc from its Oxid, Oxidized Ores, Roasted Zinc-Blende, and the Like, of which the following is a specification.

The process hitherto in use in zinc-smelting for winning zinc from oxidized zinc ores and the like consists in mixing the ore with some forty to fifty per cent. of carbonaceous material, such as coal or coke and cinders, and charging this mixture into retorts, wherein the reduction of thezinc oxid to metal is effected by the carbon when the charge is strongly heated.

To obtain the best possible yield of zinc, the particles of ore must be in intimate contact with the reducing agent and sintering or fusion of the charge must be avoided. For this reason three or five times as much coal or coke and cinders is added as is essential for the reduction. By the present invention this excess of reducing agent is avoided by substituting for a part of the latter a liquid or semiliquid substance containing a heavy hydrocarbon, such as tar, the proportion of such addition being determined by the nature of the ore to be smelted. The consumption of coal or coke and cinder is thus diminished to one-half or one-third of that hitherto necessary for reducing and preventing agglomeration of the charge. For example, an addition of three per cent. of tar and twenty-five per cent. of coal is as effective in preventing sintering and fusion of a charge as is an addition of fifty per cent. of coal without tar. By adding the reducing agent in a liquid condition a more intimate intermixture with the charge is obtained than when the reducing agent is a solid.

When the charge is heated in the retort, finely-divided carbon separates from the heavy hydrocarbon before the temperature at which reduction occurs is attained, and

this carbon incloses every particle of ore, thus preventing the charge from fusing together the reducing agent, calculated on the weight.

of the charge, three to five per cent. of tar may be substituted, whereby the smelting capacity of the reducing-furnace is correspondingly increased and the cost of smelting reduced by some twenty to thirty per cent.

Instead of tar any other liquid material or material which softens or becomes liquid when heated containing a heavy hydrocarbon or hydrocarbons rich in carbon, such as asphalt, may be used. When the material to be added softens or melts only on being heated, the material to be reduced must be intimately mixed with it after it has been heated. I am aware that tar or pitch has been used as an agglutinant for making briquets from plumbiferous zinc ores, but it is then still essential to use bituminous coal. By my invention,however,no briquetting of the charge is necessary and the smelter is not bound to use bituminous coal. Moreover, a larger proportion of liquid carbonaceous material may be used than in the briquetting process.

Having thus described the nature of this invention and the best means I know of carrying the same into practical effect, I claim A process for smelting oxidized zinc ores which consists in impregnating the ore with hydrocarbons, mixing it with a quantity of coal less than necessary for-effecting alone a reduction of the ore, and then distilling the mixture, substantially as specified.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

I/VILHELM SCI-IULTE. 

